NP993

Would be surprised if it's the a-arm bushings, as opposed to all the other suspension mods you've done.

Bill Verburg

Why would anyone be surprised when p/u bushes start to squeak. p/u is the wrong material for the application

I have 2 sets of these bushes in my junk parts bin, one is from a very low mile track car the other an indeterminate mileage street car, both show wear

chaoscreature

Bill,

Just curious, but what do you recommend?
FWIW I have used urethane bushings on everything from Jeeps to my Porsche (which has Walrod bushings installed). When properly installed and lubricated in applications where they essentially act as a bearing (meaning no off-axis rotation or translation), they work great. I have a few years on my Walrod Bushings and they made a tremendous improvement over the 15ish year old stock bushings I replaced.

Mr.Alex

Sounds like front sway bushings and/or perhaps the shop didn't hook the sway bar bracket into the control arm and its moving around. I didn't do this the first time I swapped bushings.

Bill Verburg

10000 Lemmings can't be wrong eh?
Porsche tried p/u back in the early '70s and gave it up as a bad proposition, they use rubber or uni-ball which is what I would have and do use on my car.

p/u plus it's cheap and easily manufactured in most any shape by any one.

p/u minus it relies 100% on lubrication, there is no lube that lasts forever in an open sides installation like the A arm bushes, it seeps and washes out and dries out eventually and needs to be renewed. In the mean time the p/u is wearing, the less lube the more wear. Both sets that I have are far from dry yet both sets exhibit wear.

rubber and uni-ball don't last forever either but they do last a long time.

When people choose p/u they ae choosing the low cost solution not the engineering solution, for bushes at least

Now a great application for p/u is steering rack mounts, these are not lubricated and have no sliding friction to worry about. Perfect for p/u

NP993

Just to relate my own experience with the Walrod bushings -- I installed them in early 2008, seven years ago, when they first came out. Have put more than 50K miles on them, not a small amount of it pothole city driving. No squeaks or noise of any kind.

OverBoosted28

I opted for the Walrods when I first determined my "50 mph" shimmy was most likely bushes. That was about 2010, have had the P/U bushes on the H&Rs and the above steering rack P/U bushes. Not near as many track days (and surely, not as extreme) as Bills, but as yet have not had any neg. effects. I think Bill just "abuses" his suspension, and that's a compliment :-)
As a side note, when the P/U fails, it'll be monoballs

Also, when I replaced the steering rack bushes, they could've been sprayed yellow, coated with sugar and passed for Easter candy

chaoscreature

I am also planning on doing monoballs in the rear, when I have time to make them.

I think urethane bushings have a place in suspension components, it's not a bad material but I do think it gets used in applications which it's not intended for . Urethane can't take repeated stretching/compressing. It must be used in applications where it acts like a bearing only. The front control arms seem like a good application for urethane as the two bushings rotate through their axes. The rear suspension is a whole other mess of oddly angled arms... a spherical bearing is the only viable option there (OR rubber... of course).

Bill Verburg

Sure, where there is no twist between the fixed and moveing components urethane will be fine

rear sub frame mounts, engine mounts, transmission mounts, steering rack mounts, shock mounts have minimal twist and urethane works there too. But every other suspension component on a 993 has a twisting component to it, f/r doesn't matter,

the beauty of urethane is that it does resist compression forces very well, this is what makes it stiff. It's other asset is low cost and easy manufacturability.

the bane is that it has little to no self lubricating capacity, it relies on external lube. The Lube Chris supplies must be magic to last as long as it does, but it is not permanent and will need periodic renewal. As the lube dries up stiction increases, stiction leads to heat, wear and misalignment

chaoscreature

It would be interesting to speak with Elephant Racing and ask them why they have moved away from Polybronze bushings on anything newer than the Carrera's. Delrin, Nylon, Nylatron or solid bronze all seem like viable lower cost options... for the front control arms anyways.

FlyinTomato

Bill, Would you recommend any good alternative to rubber bushings? at a reasonable price. This car is a street car. Won't see track days.

Bill Verburg

The RS had the suspension that should have been on all 993

Elephant Racing Sport Rubber are clones of the oe RS bushes
RS only uses stiffer on the trailing legs of the front A arms, I put them on both legs

to do it right
the rear A arm trailing legs and the KT arms should also have stiffer sport rubber bushes

993Buyer

I have a set available. New in box. $85 PM me if interested.
Thx. Quinn